 
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css">
  <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
  <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script>
  <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script>
<title>欢迎界面</title>
</head>
<body>
<nav class="navbar navbar-expand-sm bg-dark navbar-dark">
  <!-- Brand/logo -->
  <a class="navbar-brand" href="#">
    <img src="https://static.runoob.com/images/mix/bird.jpg" alt="logo" style="width:80px;">
  </a>
  
  <!-- Links -->
  <ul class="navbar-nav">
    <li class="nav-item">
      <a class="nav-link" href="#">登录</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">主页</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">关于我们</a>
    </li>
  </ul>
</nav>
<style>
  /* Make the image fully responsive */
  .carousel-inner img {
      width: 100%;
      height: 100%;
  }
  </style>
  <div id="demo" class="carousel slide" data-ride="carousel">
 
  <!-- 指示符 -->
  <ul class="carousel-indicators">
    <li data-target="#demo" data-slide-to="0" class="active"></li>
    <li data-target="#demo" data-slide-to="1"></li>
    <li data-target="#demo" data-slide-to="2"></li>
  </ul>
 
  <!-- 轮播图片 -->
  <div class="carousel-inner">
    <div class="carousel-item active">
      <img src="https://static.runoob.com/images/mix/img_fjords_wide.jpg">
      <div class="carousel-caption">
        <h3>第一张图片描述标题</h3>
        <p>描述文字!</p>
      </div>
    </div>
    <div class="carousel-item">
      <img src="https://static.runoob.com/images/mix/img_nature_wide.jpg">
      <div class="carousel-caption">
        <h3>第二张图片描述标题</h3>
        <p>描述文字!</p>
      </div>
    </div>
    <div class="carousel-item">
      <img src="https://static.runoob.com/images/mix/img_mountains_wide.jpg">
      <div class="carousel-caption">
        <h3>第三张图片描述标题</h3>
        <p>描述文字!</p>
      </div>
    </div>
  </div>
 
  <!-- 左右切换按钮 -->
  <a class="carousel-control-prev" href="#demo" data-slide="prev">
    <span class="carousel-control-prev-icon"></span>
  </a>
  <a class="carousel-control-next" href="#demo" data-slide="next">
    <span class="carousel-control-next-icon"></span>
  </a>
  
</div>
</body>
</html>